Nonconducting covering for boilers and other vessels



J. HAWKRIGE ET AL jmmwm NoNccNDucT 1 NG COVERING FOR Bol LERs AND OTHERVassrsa F1 LED Nov.

NoNccNDUcTING Covsieme FOR BolLERs AND OTHER VassgLs,

FILED Nov4 3.

1921. 2 SHEETS-s HEET 2 JUSEPH HAWKRIDGE, DAVID RGBERTSON, AND CHARLESJESU NAIRNE, OF LONDON,

ENGLAND.

NONCONDUCTING COVER/ING FOR DOILEBS AND OTHER VlESSElLS.

Application filed November 3, 1921. Serial No. 512,683.

To all whom it may concern:

Be it known that we, JOSEPH HAwnmnon, Devin RonnTsoN, and CHARLES JnsUNAiRNn, all subjects of the King of Great `lritain` all residing inLondon, England, have `jointly invented certain new and usefulimprovements Relating to Nonconducting Coverings for Boilers and OtherVessels, of which the following is a specification.

The invention consists in improvements relating to fire-resistingcoverings or laggings for preventing the passage of heat out of or intoboilers or other vessels.

According to the invention, millboard tubes of asbestos or of othersuitable fireresisting material are inserted in slabs composed of fibresof similar material and covered by a wrapping of woven libres also ofthe same material.

rl`hese tubes are of any required number and vary in diameter to suitthe thickness of the mattress and by the air spaces provided improve thenon-conducting property of the covering.

ln the usual practice the coverings have been made in sizes to extendover large surfaces, but their ldimensions render it dif ficult to placeand keep them in position and when repairs are necessary the lagging isoften torn and rendered unfit for further use. ccording to theinvention, these drawbacks are obviated by making the coverings of slabsof comparatively small size, for example about a foot square, which areeasily manipulated and can lbe securely linked together by meansdescribed below.

Metal sheets suitably interlocked are provided to protect the fasteningsof the coverings, more particularly at places, such as the tops of theboilers, where they are liable to be trodden on.

In the accompanying drawing which represents an example of a coveringaccording to the invention, Fig. 1 is a view showing two slabs connectedtogether, Fig. 2 is a section on the line Q-j-Q of Fig. 1, Fig. 3 showstwo slabs joined together in a slightly modified manner; Fig. 4: is asection on line 1--4 of Fig. 3. j

Referring to Figs. 1 and 2, A1, A2 are two slabs of asbestos-filledfibre enclosed in a woven wrapping of the same material; B

are tubes of asbestos mill board containing air and enclosed in thewrapping; U are hooks provided on wires D secured in any suitable mannerto the slabs nearthe edges of the latter and adapted to engage with thesimilarly arranged wires D1 of the adjacent slab. An overlapping portionE of the wrapping covers the joint between two slabs which arepreferably bevelled as shown.

Figs. 3 and l show a modified method ot' attaching two slabs'Al, A2. V Fis a. rectangle of wire secured by thin wires G to the wrapping of theslab A1; lH are metal bands of the form shown in Fig. 4f connect-ing theslab A1 with the slab A2 by a hinged joint. The end slab at each side ofthe boiler may be fastened to an angle iron by *similar means. T he wireF also serves to prevent direct contact between the slabs and the? .Y

boiler' plating and provides a thin layer of air between these partswhich lessens the thermal conductivity and allows any moisture depositedon the plating to escape. The hinge joints may be replaced by copper orother wire, lacing together the adjacent wires.

Metal sheets 'I cover theI joints, each sheet being bent back uponitself at its ends to engage with the ends of the next adjacent sheet asshown.`

Having thus described the nature of the said invention and the bestmeans we know of carrying the same into practical effect, we claim:

1. A boiler lagging comprising fibres of fire-resisting material of lowthermal conductivity, tubes of a material having similar propertiesinserted and retained within said fibres and a wrapping of similarmaterial enclosing said fibres.

2. A boiler lagging consisting of slabs of asbestos fibre, tubes ofasbestos inserted in said slabs and a wrapping of felted asbestos fibresenclosing said slabs.

3. A boiler lagging comprising small slabs of asbestos, tubes ofasbestos inserted in said slabs, wires secured to said slabs and metalhooks forming hinged joints con necting said wires on said adjacentslabs.

4. A boiler lagging comprisin small slabs of asbestos, said slabs beingevelled at the edges, tubes of asbestos inserted in said slabs, wiressecured to.said slabs and metal hooks forminghinged joints connectingsaid wires on said adjacent slabs.

5. A boiler lagging comprising small slabs of asbestos, wiressubstantially of rectangular form secured to said slabs and metal stripswith hooked ends connecting said Wires on adjacent slabs.

6. Aboiler lagging comprising small slabs of asbestos, Wires secured tosaid slabs, metal hooks forming hinged joints connecting said wires onsaid adjacent slabs, and metal sheets hooked together covering said.'oints.

7. A boiler lagging comprising small slabs ofI fire-resisting materialof low thermal conductivity` tubes of a material having!silnlilarproperties inserted in `said. slabs. wires of substantiallylei'tangulai forni ecui'ed to said slabs and metal sti-ips with 15hooked ends connecting said wires on'adjacent slabs.

ln testimony whereof we have signed 0111 naines to this specification.

JOSEPH HAXVKRIDGE. DAVID ROBERTSON. CHARLES JESU NAIRN.

